Process for recovering molybdenum from petroleum hydrocarbons



Patents Aug. 12, 1930 orrlca ALFRED OBERIiE, OF KANSAS CITY, MISSOURI I reaocnss non RECOVERING MOLYBDENUM mom PETROLEUM HYnRooARBoNs No Drawing. Application filed May 20,

This invention relates to improvements in a process for recoverlng molybdenum from .petroleum hydrocarbons, and refers more particularly to a process'in which com-- pounds of molybdenum are dissolved from residual petroleum products, such as petro leum coke, and heavy residual oils or carbonaceous materials such as the cokey substances resulting from the, cracking of petroleum hydrocarbons inthe production of motor fuel, and with a method of extracting molybdenum by consumption of the volatile and oxidizable petroleum products by the action of heat, the molybdenum being recovered as an oxide or other molybdenum compound by deposition.

Among the important objects of the invention are to provide a process in which a residual, solid or semi-solid carbonaceous mate- 2 rial is treated in a manner in which molybdenum compounds may be extracted therefrom by leaching with Water or other sol vents of molybdenum. t

It has been found that some petroleum hydrocarbons, and particularly the residual carbonaceous materials resulting from the treatment of certain oils, contain considerable quantities of molybdenum which may be easily extracted, therebv furnishing a potential supply of molybdenum which, at the present time, is relatively a precious metal supplied from a few restricted sources.

In extracting the metal petroleum coke resulting either from the distillation of oils,

residue from'the cracking of petroleum hydrocarbons, or a cokey carbonaceous material resulting from the treatment of petroleum hydrocarbons, may be heattreated either by roasting or otherwise to drive off any remaining volatile material and at a certain stage in this treatment may be subjected to the action of steam or water which serves to bring out or leach from the cokey material the molybdenum which readily goes into solution.

Where molybdenum is desired to be recovered from certain hydrocarbon oils which are to be burned as fuel, as certain of the heavy Mexican, Ohio or Persian oils, the

5 hydrocarbon products are practically com-' 1929. Serial No. 364,710.

pletely consumed in the combustion of the oil and to recover the molybdenum compounds, it is necessary to devise some method of obstructing or retarding the metal compounds by means of a deposit screen or by the use of an absorptive agent such as coke,

cinders, activated carbonaceous material,

ground'or broken up slag, spent shale, diatomaceous earth or other absorptive substances which would serve to extract the molybdenum compounds from the combustion gases. Subsequent to this separation,

the molybdenum compounds may be dissolved from the absorbent material.

In the case of burning oils the recovery of molybdenum compounds is best effected by a process in which during the consumption of the oil molybdenum compounds which may be carried off mechanically in the form of fine particles'in the combustion gases, are arrested and deposited in an absorbent body or upon specially prepared wire screens or any other type of obstruction devices which effectively prevent the passage of the metallic molybdenum and cause the same to be deposited in the absorbent material to'be later recovered by extraction with a solvent.

An absorbent material is used with the best effect by being interposed in the form of a tower in the path of the combustion gases so that the gases are directed through the tower and through the absorbent material in their travel to the stack or atmosphere.

In order to relieve flue gases or combustion gases from their contents of molybdenum, the gases are led through any suitable bubble tower arrangement containing water, acidulated water, or any suitable solvent for molybdenum. Instead of bubbling the gases through liquids, the liquid maybe sprayed counter currently to the flow of the gases.

Under certain conditions it has been found advantageous to add, to the solid carbonaceous material undergoing treatment, an absorptive material such as coal ashes, coke ashes, coke, cinders, ground or broken up slag or any absorptive material such as a porous coke or activated carbon preferably such material as is claimed in my prior application Serial No. 67 2,648, filed November 3 1923.

If the material is treated with an activated carbon such as a spongy absorptive cokey material as that explained in my, prior application, it is important that additional oil residue be added from time to time as dur ing the treatment the material will itself become absorptive due to the driving off of the volatile materials.

Subsequent to the leaching operation, the cokey residue may again be heat treated and will, with successive heat treatments and leaching operations, give up molybdenum in the manner described.

The function of the absorption material, such as the activated carbon, coal ashes, fullers earth, or innumerable other absorptive materials including diatomaceous earths, kaolins or colloidal clay such as bentonite, is to draw off from the cokey material molybdenum which may be subsequently extracted by leaching as described.

Where oils containing molybdenum are used in internal combustion engines, such as heavy types of Diesel engines, any molybdenum content may be recovered from the exhaust gases by interposing an absorbent body of activated carbon coke or other relatively inert absorbent materials in the ex-' haust line, 'or passing the gas through a suitable liquid such as water. The molybdenum is normally deposited as a molybdenum oxide which is easily dissolved from the-absorbent material with a proper solvent.

mea er:

in heat treating a residual cokey hydrocarbon in the presence of an absorptive material, driving off the volatile material by said heat tfieatment, concentrating the molybdenum content of the mixture by periodic additions of hydrocarbon material containing molybdenum, sub ecting the mixture to successive leaching action with a molybdenum solvent and treating the solution to recover the molybdenum compounds therefrom.

4. A process for extracting molybdenum from petroleum hydrocarbons which consists in heat treating a residual cokey hydrocarbon in the presence of an absorptive activated carbonaceous substance, driving off the volatile material by said-heat treatment and continuing the-heating, concentrating the molybdenum content of the mixture by additions of hydrocarbon material containing molybdenum, subjecting the mixture to a the leaching action of a solvent of the molybdenum compounds and treating the solution to recover therefrom molybdenum compounds.

ALFRED OBERLE.

As a suggested manner of carrying out the prefered procedure, a cokey residual substance such as petroleum coke recovered from a cracking plant, is combined with an absorptive activated carbon and is roasted in a closed retort until substantially all of the volatile material has been removed. From time to time portions of the material undergoing treatment may be removed from the retort and water added thereto as a leaching fluid. The material, when sufficiently treated, should be leached with a solvent such as water which readily relieves the treated substance of a portion of the molybdenum,- the molybdenum combining with the solvent form a solution.

I claim as my invention:

1. vA process for extracting molybdenum from petroleum hydrocarbons which consists in heat treating a residual cokey hydrocarbon in the presence of an absorptive material, driving off the volatile material by said heat treatment, subjecting said mixture to the leaching action of a solvent adapted to dissolve molybdenum com ounds and finally relieving the solution 0 its molybdenum content.

2. A process for extracting molybdenum from petroleum hydrocarbons which consists in heat treating a residual cokey hydrocar- 

